Occasional Babysitter For Two Little Ones

My husband and I would like an occasional, but consistent date night together. We would ideally love to go out for a couple hours in the evening when our kids go to bed, mostly between the hours of 6-10 p.m. We are looking for someone to watch the boys (20 mo and 5mo) while they sleep and be present for emergencies, as our children are usually asleep before 7, and we intend to have all the bedtime cares and meals complete.